Receiving device for subaqueous sound-signals



w. HAHNEMANN AND H. HECHT.

RECEIVING DEVICE FOR SUBAQUEOUS SOUND SIGNALS.

APPLICATION FILED JULY 10,1914. RENEWED JAN. 9, I9I9.

1,391,681 PatentedSept. 27,1921.

.water. This shape of bysome kind of structure, it

UNI-"rep smi e A E T-or fice.

WALTER HABNEMANN, or xrrznnnne, NEAR KIEL, AND HEINRICH macaw, or me,

. GERMANY. I

, RECEIVING DEVICE FOR SUB-AQUEOUS SOUND-SIGNALS.

Specification of Letters Patent.

latented Sept. 27, 1921.

Application filed July 10, 1914, Serial No. 850,185. Renewed January 9, 1919. Serial 110. 270,441.

To all whom it may concern Be it known that. we, WALTER HAHNE- MANN and HEINRICH Hncn'r, subjects of the German Emperor, residing, respectively, at Kitzeberg, near Kiel, and Kiel, 65 Feldstrasse, in the Kingdom of Prussia, have-invented certain new and useful Improvements in Receiving Devices for Subaqueous Sound- Signals, of which the following is a specification.

This invention relates to a receiving device for subaqueous sound signals which is so arranged that the sound waves arriving from a-distant point impinge .upon a receiver that is placed in the exterior water; that is, .the water outside. of the signaling station or the water in which the ship con-- taining the signaling station is floating. A

known arrangement consists in mounting microphones, that which. act as receivers, in spherical vessels, and in vessels so that they hang over the side of the ship and are zth us suspended in the vessel givesthe greatest possible security against pressure? but it has a great drawback in that it gives rise to the formation of eddies during the motion of the ship, thus creating disturbing noises or'vibrations in the receiver. The'idea underlying this design of vessel seems to have been that by surrounding the microphone .with liquid on 'all sides disturbing noises would not be imparted-- to the microphone. But it must be observed that, since, th microphone requires tobe fixed in position is not possible to attain a really perfect isolation of the microphone. It will be seen, that any arrangement will be advantageous which'censtitutes a step toward the suppression of disturbing vibrations or noi ing an arrangement of this kind due regard may also be had to the'aforeinentioned endeavor to protect the device against the pressure of the water.

The present invention consists of an arrangement which has these advantages; and the essential feature of which is that the receiver, e. 9., the microphone, is laterally inclosed in a protective envelop, the outer surfaces of which are so shaped as to offer the least possible amount of resistance to the water that washes past them. In addition to this measure it is, of course, necessary to mount the entire device in a suitable manf the arranging these es. In d'esignner; namely, inwsuch manner that the horizontal longitudinal axis of the vessel or envelop containing the receiver will-lie in a direction that is the same asor'substantially parallel to the direction of the axis of the ship. Q I A further recognized fact underlying this inventionis that this way device will not be advantageous at all parts of the ship; and since receivers are often fixed to the bow or stem of the ship, another may of mounting the device must be employe in such cases.

fixmg the horizontal longitudinal axis of envelop in such position that it coincides with the current lines of the water. By this means the occurrence of a pressure component that would be caused by water curin ad rents or current linesstriking the envelop irection at an angle to the horizontal 0ngitudina1"axis of the enveloping surfaces The direction of flow of the water curlongitudinal This consists in I is of substantially v8 0 rent lines approximately conforms to the contour of the ships hull, so that if the receiver is mounted at the bow or stern the horizontal longitudinal axis of the body or envelop containin erably be arranged to lie at a suitable angle to the longitudlnal axis of the ship in order to obtain the best results, In accordancetwith the invention it will sometimes be found suflicient to provide surfaces at the side of the receiving device, that areparallel to the ships hull, but it will generally be more advantageous (especially if he receiver is to be made protrudable through the shi s' side) to provide surfaces that inclose the receiver at all sides and form a watertight en'velop.- These enveloping surfaces will be curved so as try embody stream-line principles, as for. example in the shape of flattened hemispheres, such asthe receiver would prefs shown in Fig. 4, inorder to make them offer the greatest possible resistance to the pres sure ,of the wet r while alsomaking them 'easy..to construct.- The plain s he'rical sha e of envelop was mentioned a we, and we disadvantages were i1pointed out.

v Fi ures 1, and. 2 ustrate difierent forms phone is I inclosed laterally receiver comprising a microphone M is fixed at the ships side in the 'zone of the current lines about the bow of a ship S. The shape ofthe current lines is, as indicated in the drawin approximately. that of the ships sides. ccording to the invention the microbfv surfaces F- forming a protective envelpp or the microphonefl These surfaces join at two ends and are shaped as illustrated in Fig. 3.

v microphone may be heldin position by rubber cords. The horizontal longitudinal axis of the envelop lies in the direction of-the current lines, or forms a tangent with these lines at It is assumed that the device is attached to the ships side, as indicated in Fig. 2, by

l' slender and light fixture.

a rigid rope or the like which contains the electrical conductors leading to the micro phone. The vertical dimensions of the enveloping surfaces of the device shown in Figs-'1 and 3 is such that the water inclosed between them is quite quiescentso that the microphone can be held by a comparatively In the example described and shown in Fi land 3 the water is not kept out of the inc osed space. But in the example shown the point where the device is fixed.

toward the front and rear so as to approximate stream-line form and offer the least possible resistance to the water.

We claim:

1: Asubmarine sound si naling plant in combination with a vessei comprising "a sound receiver surrounded by a rotective envelop consisting of plates latera 1y inclos ing said receiver and rigidly connected with said vessel; said envelop being arranged in the passing water, and being of substantially stream-line form and arrangement to prevent the formation of eddies in the passing water.

2.'A submarine sound si naling plant in combination with 'a vesse, comprising a sound, receiver surrounded by a protective envelop consisting of 4 plates laterally inclosing said receiver, and means carrying said envelop rigidly connected-with said ves sel; said envelop beingarranged in the passing water, and being of substantially stream-line form and arrangement to prevent the formationof eddies water. 7

In'tes'timony whereofwe alfix our signatures, in presence of two witnesses.

WALTER HAHNEMANNI 3 DR. PHIL. HEINRICH H CHT. Witnesses;

J uLrUs Riirxn,

KARL Fmr'mmon Fmueu'r.

in the passing- 

